Treatment of zinc-lyes.



' To allj'whomit may concern: V

' .f Beeit known that I, Dr. WILHELM BUD- onus, a subject of theDuke of Saxe-Ooburg- 'Goth'a, and resident of f Charlottenburg, German Empire, have invented certain and useful l 'nprovements' inj the Treatment of nyp extraction -z1nc from Z1110 lyes containing ferrous iron, such for exam le as'the waste WILHELM BUDDEUS, or cHAntorrEivBU-ns, GERMANY.

rmiammfimr or zinc-runs,

1,120,683. Fomwiiig,

Zinc-Lyes, of which "the following is a specification. Q

osals' have been made for the lyes obtained in processes 0 copper extrac- "tion, by means of iron, from copp'er ores containing zinc; the methods hithertosug-r gested have been found impracticable or too costly, with the r'esultthat, notwithstanding it kthe considerable quantities ofzinc that such lyes contain, they'yhave not been utilized;

moreover, if the lyesiaredischarged into streams they contaminate andpoison the W Water.

Two-stage proo consisting in first I converting the ferrous iron to theferric. j state by oxidizing agents ,such aschlorin or nitric acid andflthen precipitating .the ferric iron with basic material, such as i lime, calcium carbonate, and the like, are a of small account practically, owing to the a bases or carbonates and then blowing air high price of the oxidizing agents. Also,

the oxidizing of thefferrous iron by adding through, does not'lead to complete: oxidation andrequlres so much time and so great I a quantity of compressed air that, technically speaking, it is impracticable to treat large quantities of the zinc lyes to a useful extent. Consequently this process, of oxidation has been abandoned in practice; it

presents the further defect that all the salts and the total quantity of chlorin remain in the lye and thereby'render the extraction T of the zinc in any form a difficult andexpensive matter, I I

According to, the present lnvention the zinkiferous lyes containingiferrous lron are treated with an amount of bases such asi 1 burnt lime, magnesia or ground lime stone, 1 soda etc, su'fhclentto precipitate all the zinc andall the ferrousjiron, the'sliiny mass obtamed by filtrationand washing of the precipitate is then dried in such a way as to cause oxidation of, the ferrous iron com- Specification of Letters Patent. Patented Dec. 15, 1914.

Application filed November 2c, 1913. serial N9, 603,201.

pletely to the ferric state the dried mass is then treated with sufficient acid to remove the zinc compound, this being the constitu cut most readily attacked by the acid. The

zinkiferous lyes treated may be the wastlyes from the known process of extractionfl of copper, 'bymeans-0f iron, from zincf copper ores or metal waste in general con-f taming copper and zinc;

I f lime is used for the complete precipi- 'tation of the zinc and ferrous iron, the slimy mass resulting from filtration and leaching of the precipitate contains calcium sulfate as well as the iron and zinc oxids. During a the drying of'the mass, which is done by means of air, the ferrous oxid is oxidized completely to ferric oxid, as already stated. From the resulting product, consistin of ferric oxid, zinc oxid and calcium'sulfate,

the zinc can be removed in the form of-zinc salts by treating with acids in the known manner, since the zinc oxid is dissolved by the acids before the ferric oxidJ All that is necessary is to use a quantity of acidcob responding to the amount of zindcontainedj in the product under treatment, and to,

eliminate the resultant 'zinc salt by and pressing.

The pure zinc metallic zinc, as desired.

Having now particularly descriliedhzid ascertained the nature of my said invention and 'inwhat manner the same is to be per:

formed, I declare that what I claim is v The treatment of zinkiferous lyes con I 80 lyes free fromjron thus obtained can be treated by known methods to form other zinc compounds or The foregoing specification signed at Magdeburg this 17th 'DR. l/VILHELM BUDDEUS;

In presence of two Witnesses:

FRIEDRICH Smrnn, VVILHELM FLEISCHHACK.

day of November, 4 

